What is defined as a mathematical sentence that uses an equals sign to show equality?

A mathematical sentence that uses an equals sign to show equality is known as an equation. An equation states that two expressions are equal to one another, which is represented by the use of the equals sign ("="). For example, in the equation 2x + 3 = 7, both sides of the equation are equal, indicating a specific relationship between the variables and constants involved.

In contrast, an inequality expresses a relationship where one side is not necessarily equal to the other, using symbols like "<" or ">". An expression, on the other hand, is a combination of numbers, variables, and operations but does not include an equals sign, hence it does not indicate a relationship of equality. A formula is a specific type of equation that expresses a mathematical relationship or rule, typically involving variables to represent different quantities but can still be classified as an equation when it asserts that two values are equal.